Warehouse work at food banks, Construction on habitat for humanity and green builder programs, community garden and park revival projects.
The book/website would outline opportunities and focus on how the real world experience would translate into actual exercise and learning opportunities.
This is not meant to replace your gym workout completely, but to augment it and break the routine, while contributing to the community.
The book could be the primer and the website would be a place for organizations to list upcoming opportunities.
exerciseCharity.com is available